Autopage doesn't want to blacklist my phone

I bought a phone from foschini a while and I have been using an Autopage sim card(contract) on this phone, I got ****** on Friday and they took my phone, I am now struggling to block this phone. Autopage advised me that they cannot help me as the phone is not theirs, foschini cannot blacklist this phone as my service provide has to do this. I have been going back and fort trying to resolve this and noone can help me. I need this phone blacklisted as I have to obtain an ITC number in order to claim from my insurance. Autopage should be blocking this phone as they are my service provider but I am not getting any joy on this matter.